Finished my Auto Topoff!
 

Finally, after weeks of studying and looking for parts its done!

http://www.members.shaw.ca/harvwong/12.22.04/Float2.JPG
http://www.members.shaw.ca/harvwong/12.22.04/Float3.JPG

There is only 24VDC running through the float switch. Once the switch closes, the relay trips and the powerhead pump starts up. What do you guys think? One bad thing about it though is that the cord to the switch is so short. I might have to splice some wires, but then it won't look as clean.

Very nice...wow might just be the inspiration I needed to give it a go on my own :idea:
Where did you get your float switch and relay?

Hey thanks!

The float switch is from Ivan @ Aquaria Canada. The relay I picked up form Active Electronics. I'm sure you could get one online from DigiKey or Newark for cheaper.

Thats a really nice looking switch... :mrgreen:

looks good, what made you decide to go with a powered top off instead of a gravity system?

Steve

I actually built this for a friend of mine who doesn't have a sump. On my current system, I'm trying to get a feed from my RO unit through a float valve...now if only I could get my dishwasher out of the way :evil:

Hey,looks like the one a good friend built for me :mrgreen: ...what are the odds?(thanks again :biggrin: )

I would not conect them directly.. there is a small chance that the check valve could fail causing your RO to continue to top off your tank and drop your salinity and make a mess. best to isolate the two.

Steve

Steve

What's the gravity feed system all about?

Dave

Isnt gravity feed just a holding tank with RO water above sump level then a float valve in the sump, when the water gets low in the sump the valve opens to the holding tub and tops it off?

yup, I have a 110gal resavoir above the tank highet to a float valve. I like this as it will work with no power (less to go wrong) I just fill up the resavoir every month I have gone 2 months befor having to fill it.

Steve

What happens if your float valve fails with 110g of freshwater?

Nice DIY job, btw!

In both situations if the float value fails you have a problem/same problem don't you?

Dave

Oh ya very nice DIY job for sure, what do you think it cost you to make?

The total cost for everything was roughly $50.

Would it be possible for you to post a part list, where you got them and the plans? I'd like to make it too! (Excellent work!)

While I don't have an exact parts list, I can tell you what I used:

Essentials
Project Box ~$7 (Active Electronics)
120VAC -> 24VDC Transformer ~$13 (Active Electronics)
Float Switch ~$12 (fellow reefer)
DPDT Solid State Relay ~$5 (Active Electronics)
Extension cord (10m) ~$10 (Cnd Tire)

Misc Parts/tools
Solder
Grommets
Merets
Twist Ties
Old 35mm film cannister
Door hooks
Nylon nuts/bolts
Multimeter

It took me about 1 hr to do. The longest part is the hanging bracket. Takes me forever to drill all those little holes.

I don't have a schematic as I didn't really follow a particular one. I had my friend who has done a lot with electronics come by and help me figure out the relay as I've never used them before, but once that was sorted out, it went fairly smoothly. You can use this schematic taken from ReefKeeping.com:
http://reefkeeping.com/issues/2002-0...ges/topoff.gif

(if the picture doesn't load, go to the article found here:
http://reefkeeping.com/issues/2002-03/jg/index.htm)

A couple of things I don't like about this particular box is that 1)the wires from the switch are very short. As a result, if you are mounting the float switch in your tank, you'll need to put the box either in your canopy or somehow mount it on the aquarium since the cord won't reach if you place it on the floor. 2) the box is quite large. I need to figure out a way to cram everything into a smaller box so it doesn't take up as much space.

This was how I was going to hook my RO/DI system to my tank via a float switch. The solenoid is in the off (closed) position until the float switch calls for water and opens it...I guess the only way it could fail is if your float switch got stuck in the down position some how...the same idea as the ones used on reactors except this one is all plastic instead of brass. The one question is if you are using this for RO why couldn't you use the brass one if it isn't coming in contact with the salt water?

http://www.canreef.com/photopost/dat...noid-thumb.jpg

Hi, if you still need a schematic there is one in this thread:

http://www.canreef.com/phpBB2/viewto...738&highlight=

For extending the wiring to the float switch I used some wiring of the same gauge and used a 2 wire connector that I got at Radio Shack for a couple of bucks. It also makes taking the float switch out for cleaning a breeze. I also used a manual on/off switch which I use for water changes as I am sump less.

Hope this helps

Dave

Hi Dave,

Did you use a solid state relay or a mechanical relay on your auto topoff?

Harvey, well I don't know much about electronic gadgets but I think it is solid state. It is a small sealed black device with connections on it and it goes click when energized :crazyeye:

Are the mechanical relays clear so that you can see the contacts? Told ya I don't know much about this stuff!

Dave

Solid state relays just look like tiny black boxes with prongs sticking out the bottom (well all the ones I've ever seen were). A mechanical relay usually has a clear portion on the top where you can see the "guts" of the relay.

If it goes "click" it aint solid state. :smile: many of the mini mechanical relays are in sealed black cases.

The color of the case has nothing to do with it......If you look on the case it will say Coil Voltage, those are mechanical!!!